Rifle barrel lapping machine



Occ. 13,1942. A; RAICHE 2,298,775

` RINFLE BARREL LAPING MACHINE' Filed May-16, 1941 616 77.7."1" 1/1/1/1/1/1/1/1 n f/ 'l' l eliminated.

Potented oet la, 1942 f ns N ,PATE y `attraits 'r v meinem OFI-les y t, j y Apoliontion mils, im', No. 393.199

l 1l`ciniinn.-.ic l.'s`lss) Y.

, lnppingt'ooi by hydraulic means. uuid being used the bore of a gun barrel and "thevriing `thereof.`

This invention relates to a machine for, lapping `It has been usualin the lapping oi' the rifled A'bore of a gun fbai'relto force the lappingtool t" ough the barrel back and forth by reason vof t e long ram rod. This ram. rodfoccupies considerable space and reduires the force to be apt pliedthrough the longl length rod which is untools during the completion of theoperation'.

one of the objects or this invention is to prol vide a machine which will be more compact in that the long ram rod for forcing; the lapping tool back and. forth through the barrel will Vbe Another object of` theinvention is'` to provide a lapping .tool which may be used for lapping the l lands of the barrel and thereafter expandedwithout removal from the` barrelv to lap the helical rling'groovethereof. v

' Another object of the invention is to 'provide an arrangement so that the force applied tothe lapping'tool may be through hydraulic means.

A further' object of the invention is to utilize this hydraulic means'for expanding the tool after the lapping of the lands for thereafterj lapping t oithe riiling groove.

with these and other objects in view, tue invention consists of certain novel features otconstruction, as will be more fully described and particularly pointed out inthe appended claims.

`In the accompanyingdrawing l j Fig. 1 is a top plan view illustratingthejmain 1, t t v Fig. 6 `is n section on substantially linev s-s of Fig. l:

Fig. 7 is a sectional In order to avoid 'the use yof a long rod for manipulation of a vlapping tool, I have provided thelapping tool of a soft Vmaterial `which may be expanded upon exercise lof substantialipressure and haveprovided for the reciprocation of `this Vview in detail of thev plug.

to torce the lapping tool first in one direction and then in the other direction. 'means being projvided for the travel or supply and withdrawal of the'ilnid on opposite sides of the lapping toolas the same is reciprocated. The lapping tool may be expanded so'the lapping tool will enter the helical groove of the barrel and then the lapping continued that the grooved or ried portion ofthe barrel may be lapped. l t With reference te the drawing. I0 4designates a bed plate upon which I have provided a fixed heed i i` and u movable head iz. The fixed head contains a hydraulic chamber having an opening I4 and a. soft packing I5 suchas of "neoprene surrounding the opening I4 and for the reception of one end It or thegun barrel designated generally Il.` The other head I2 is slidablymounted ongibs I8 and has a hydraulic chamber I9 provide'd with an opening 20 about which there isV soft packing 2| such as neoprenemfor thereceptlon'r of the threadedend 22 0I the barrel I1. When this head I2 is moved toward the head II witnthe orrelin the position illustrated in Fig. 2,v 4 the sott'packing forms vil. tight connection between the chambers' I3 andIS and the bore of -the barrel I'I. The head I2 may be moved toward to the bed plate by means 0f bolts 21.

and from its position of sealing the barrel in place by means ofthe threaded shaft 23 and wheelr 24 having handle 25 thereon, the same being 'threaded through a standard 26-secured Air valves i' 2l are provided in each of the chambers I3 and I9.

,The chamber Il has conduit 30 connecting it to the ycylinder' 3I .(see also Fig. 6) while the chamber .I9 has a exible conduit 32 connecting of Fig. 2 prior substantially line oi' n itto cylinder I3 (see also 6). Between these cylinders a rod I4 is provided forming a piston plunger for the cylinder 3i` and piston plunger 3l for the cylinder 33, the rod being provided with rack teeth 31 between these portions which engages with a pinion 38 on shaft 39 for the manipulation thereof. y

The cylinders 3l and 33 are supplied with uid through common pipe 40- communicating with conduit 4I and supply pump 42 operated by motor 42 and connected asat 44 to any suitable supply line. I'he transmission conduits 30 and 32 are connected together by conduit 45 having ashut-o valve 48 therein and form an arrangementfor a drain of the chambers' I3 and I9 byshaft I9.

is used to actuate thelapping tool.

i der to provide this lfunction, I desire'yto change I into trngear box 758 from which.

bevel gear 54 is drlven continuously in one direction. Shaft 88 has looselymounte'd thereon bevel gears 55 and 58 meshing gear 54 while between these'gears there .is a clutch 51 keyed-on This Aclutch. may be moved into engagement either with gear 55.or gear 55 by lever 51 pivoted as at 58 and operated electrically such as by solenoids 58 and 80 to throw the end 6| of this lever back and forth. It will be apparent that when the bar 8l is moved to the left, as shown in Fig. 6, so that its plunger 35 moves into the cylinder 8l, the liquid is going to be forced from the cylinder 3l and into the endIG of the barrel l1 to force the lapping tool 85 to the right as shown in Figs. 1 and 2, and this movement will occur until the rack terminates such movement or is driven in the opposite direction.

In order to provide for this opposite drive, I have provided electrical connections 66 and 81 in the cylinders I I and l2. Each of these consists oi.' a flexible contact 68 which is insulated from the chamber andprovides a means for electric wire 68, 69' to establish a communication into the middle. portion of the chamber without shortcircuiting to the ground of the chambers Il and I2. 'I'he iluid used will be a non-electrical conductor. The lapping plug 85 is 'an electrical conductor and as it moves through the bore toward the end of its stroke it will contact the flexible wire 68 at one end and at the same time will be in communication with the wall edges about the opening 20 and thus will form an. electrical connection from the flexible contact 68 to the ychamber and complete the operating circuit through the electrical wires (to be'described) to the solenoids to reverse the drive of the pinion 38 and consequently the flow of the liquid which There will be suilicient flexibility in the contact. 88 so that the time element for reverse will be accomplished for the mechanical shifting of the clutch to perform the desired function.

Electrical circuit of the solenoids for performing this shifting may be traced from the battery 10 through line 'Il to the ground or cylinder l2 while thelead-in wire 69 will extend to solenoids 66 and thence from solenoids 68 through line 12 and 18 back to the battery. 'I'he wiring connection to the other electrical connection in chamber Il is from battery 10 through line 69' to the chamber, thence through line 14 or the ground from the`head Il to the solenoid 59 and thence back through wire l5 and common line 13 to the battery.

It will be understood of course that the areas of the end of the plug 65 are greater than the total cross sectional areas of the grooves in the barrel so that the plug will reciprocate rather than the iluid passing by the plug through the grooves of the riing.

By the arrangement so far described, it will be apparent that I may automatically. reciprocate the plug 65 placed in the barrel I1 and which plug is cylindrical in shape, until the desired lapping has been performed on the lands of the barrel. LA tapered bushing 18 in the enlarged threaded end of the barrel provides for a cylindrical surface for the guiding of this lapping plug.

After the lapping of the lands has been provided for, with the tool 65 in the shape shown in cross section in Fig. 3, it is desirable that lapping be .provided for the grooves 80 which have been previously formed in the barrel and in or- 75 the shape of the plug 85 which will be of lead or some soft alloy. e v

The plug 85 is formed of some soft metal such as leador an alloy of lead and is molded about -a steel pin having an enlargement 8l to precause the portions thereof to enter the rifling grooves into Vwhich this plug is expanded upon the application of the hydraulic pressure thereto.

For expanding of the tool 85, I have provided a connection 8| (see Figs. 1 and 5) to the conduit 80 with the conduit 82 connecting to some means for boosting the pressure in the system. The bar 34 will be stopped at some location so that the tool 65 will be intermediate the. ends of the barrel along a portion thereof when riiling occurs. Thevalves 48 and 48 will be closed. The application of pressure from the booster will be applied to the end surface 83 of the plug I5 and will be resisted by reason ofthe end surface 84 of the plug which cannot move because the uid in the system cannot flow. 'I'hese surfaces will be of areas considerably greater than the cross sectional areas of the grooves which are to be lapped and the plug being of soft expandible material will expand into these grooves becoming' foreshortened in an amount necessary for the ilowing of the material into the grooves; and after this has been performed, pressure will be released and the lapping will continue with the plug now in the shape shown at 85 (Fig. 4) until the grooves 88 have been lapped.

I claim;

1. A machine for lapping the bore of a gun barrel comprising spaced supports having means thereon for mounting a gun barrel therebetween, a lapping tool in the barrel, bore, a closed circuit including a liquid in said gun barrel, means for applying a force on the said ,liquid from either end thereof to move the same therein to act upon and propel through the bore of said gun barrel said lapping tool positioned therein, and electrical means for alternately reversing the direction of the application of force to the fluid in said gun barrel, comprising a circuit having a normally open contact positioned in the path of travel of said lapping'tool to be engaged and closed thereby.

2. A machine for.l lapping the bore of a gun barrel comprising spaced supports having means thereon for mounting a gun barrel therebetween, a lapping tool in the barrel bore, a closed circuit including a liquid insaid gun barrel, means for applying a force on the said liquid from either end thereof to move the same therein to act upon and propel through the bore of said gun barrel said lapping tool positioned therein, and electrical means for alternately reversing the direction of the application of force to the iluid in said gun barrel comprising a circuit having a normally open contact in each of said supports and positioned in the path of travel of the said lapping plug to be engaged and closed thereby.

3. A machine for lapping the bore of a gun barrel comprising spaced supports having means thereon for mounting a gun barrel therebetween and each provided with a chamber therein communicating with the said gun barrel, spaced cylinders provided with conduits leading therefrom.

to said chambers, means for introducing a fluid into said cylinders, chambers and gun barrel and means for alternately applying a force first on the fluid in one cylinder, then on the fluid in the other cylinder to move the same to act upon and propel through the bore of said gun barrel a lapping plug positioned therein.

4. A machine for lapping the bore of a gun barrel comprising spaced supports having means thereon for mounting a gun barrel therebetween and each provided with a chamber therein communicating with the said gun barrel, spaced cylinders provided with conduits leading therefrom to said chambers, pistons mounted for reciprocal movement in said cylinders, means for introducing a fluid into said cylinders, chambers and gun barrel, and meansfor alternately moving said pistons to apply a force on the fluid in said cylinders to move the fluid to act upon and propel through the bore of said gun barrel a lapping plug positioned therein.

5. A machine for lapping the riding of a gun barrel comprising spaced supports having means thereon for mounting a gun barrel therebetween, a lapping plug in the bore of the gun barrel, hy-

draulic means comprising a fluid movable within the bore of said gun barrel for propelling the plug .through said bore, means for arresting the flow v of fluid on one side of said plug,` and means for applying simultaneously a hydraulic force on the opposite side of theisaid plug sufficient to longitudinally compress and laterally expand the plug in said bore.

y 6. The process of forming a lapping plug to conform to the shape of the riiiing of a barrel to `be lapped which consists in placing a cylindrical plug in the barrel and then applying pressure simultaneously on its opposite ends to expand the plug. laterally into the riflng grooves of the barrel bore.

7. The process of lapping the rifling of a gun barrel which consists in first reciprocating in the bore of said gun barrel a lapping plug of a size to lap only Vthe lands of the rifling, then applying a sufficient force on said plug While in the bore to ilovv.r material therefrom into the channels of the rifling, and then continuing the reciprocating of the enlarged plug in the said bore.

8. The process of lapping the riing of a gun barrel which consists in rst hydraulically reciprocating a lapping plug of a size to lap only the lands of the rifling, then applying an hydrau-` lic force on said plug while in the bore suiiicient- 1y to flow material therefrom into the channels of the rifling, and then continuing the reciprocation of the thus enlarged plug in the said bore.

9. 'I'he process of lapping the rifling of a gun barrel which consists in first hydraulically reciprocating a lapping plug of a size to lap only the lands of the rifling, then applying an hydraulic force on said plug while in the bore suiliciently to expand said plug diametrically into the riling channels, and then continuing the reciprocation of the thus enlarged plug in the said bore.

10. A machine for lapping the bore of a gun barrel, comprising spaced supports having means thereon for mounting a gun barrel therebetween, a lapping tool in said bore, a closed circuit including a liquid in said gun barrel, a cylinder having a conduit leading to said bore and a piston in said cylinder operable for applying a force on said liquid to move the same through said gun barrel to propel said lapping tool through vthe said bore, and means engaged by said lapping tool and operable for controlling the action of said piston.

11. A machine for lapping the bore of a gun Y barrel, comprising spaced supports having means thereon for mounting a gun barrel therebetween, a lapping tool in said bore, a closed circuit including a liquid in said gun barrel, a cylinder having a conduit leading to said bore and a piston in said cylinder operable for applying a force on said liquid to 'move the' same through said gun barrel to propel said lapping tool through the said borel a reversing clutch operably connected to said piston, and means engaged by said lapping tool and operable for controlling the action oi said clutch.

ANDREW RAICHE. 

